JPH09112367A - Air intake duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably reduce the generation of intake vibration at a lower cost than a conventional cost. SOLUTION: A first partition wall 14 extending upward from the vicinity 14a, serving as a starting point, of the lowerer part 13a of a duct body 13 is formed at the lower part of a duct body 13 fixed at a carburetor connected to the lower end of an air cleaner through a boot and in such a manner to erect upward, and the upper end of one duct passage of duct passages into which a duct passage is divided by a partition wall 14 is closed to form a side branch 15. A second partition wall 14' extending from a position, serving as a starting point, separated away from the upper end of the first partition wall 17 to the vicinity of the upper end opening part 17 of the duct body 13 is arranged in an inclining state at the upper part of the duct body 13 so that the duct passage is divided by the first partition wall 14 into duct passages by the other duct passage (an intake passage 16) of which the flow of intake air 19 is straightened and to the other duct passage of which the straightened flow is guided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air intake duct.

[0002]

2. Description of the Related Art Generally, large vehicles such as trucks have more opportunities to drive on unpaved rough roads than passenger vehicles, so the intake air of the engine is not the air near the ground, which contains much dust, It is advisable to take in clean air above ground level.

Therefore, in a large vehicle, as shown in FIG. 5, the air intake duct 5 fixed to the rear panel 4 of the cab 3 is flexible with respect to the air cleaner inlet duct 2 which is connected to the air cleaner 1 so as to be upright. The air intake duct 5 is connected via a boot 6 to suck in air from the upper end opening 7 of the air intake duct 5. Further, the hood 8 prevents the rainwater and the fallen leaves from directly entering the top of the air intake duct 5. Is attached.

Since the air intake duct 5 is generally formed by blow molding or the like to have a relatively large cross-sectional area and a thin wall thickness, intake air vibration is generated by pulsation of air generated in the intake stroke of the engine. This is a factor that causes the intake vibrations to be transmitted to the cab 3 to generate indoor noise (muffled noise).

Therefore, conventionally, as shown in FIG. 6, a resonator 9 (a cavity resonator to which the Helmholtz resonance principle is applied) is provided at the outlet of the air cleaner 1 so as to correspond to a specific frequency.
7 or 10, or by forming a partition wall 10 on the upper side of the air intake duct 5 as shown in FIGS. 7 to 10, the rigidity is increased and one of the duct passages divided by the partition wall 10 ( The upper end of the left side passage in FIG. 7 is closed to form the side branch 11 (resonator having a closed tube structure).

[0006]

However, when a plurality of resonators 9 are provided at the outlet of the air cleaner 1 as in the former case described above, it is expensive to manufacture the resonator 9 so as to resonate at a specific frequency. In addition, there is a problem that a plurality of resonators 9 are required, resulting in a high manufacturing cost and a high cost.

When the side branch 11 is formed in the upper portion of the air intake duct 5 as in the latter case, the length of the side branch 11 is set with the upper end as a starting point so as to match the frequency of room noise. As a result, the partition wall 10 is cut off only at the upper portion of the air intake duct 5, and the lower portion of the air intake duct 5 still has a structure in which intake vibration is likely to occur. There was a problem that the noise reduction effect could not be expected for indoor noise caused by vibration. In addition, the upper surface 10a of the upper partition of the side branch
There was a problem that a vortex air flow was generated and the intake efficiency was poor.

The present invention has been made in view of the above situation, and an object of the present invention is to provide an air intake duct that can reduce intake vibration reliably and improve intake efficiency at a lower cost than before. .

[0009]

According to the present invention, a duct main body is connected to an air cleaner at its lower end through a boot and is fixed to a cab so as to stand upright. A side wall is formed by forming a first partition wall extending a required length upward and closing an upper end of one duct passage divided by the partition wall to form a side branch, and the first partition wall is provided on an upper portion of the duct body. The second partition wall extending from the position separated from the upper end of the duct body to the vicinity of the upper end opening of the duct body so that the intake air can be rectified and guided to the other duct passage divided by the first partition wall. The present invention relates to an air intake duct characterized by being arranged.

According to this structure, the length of the side branch can be set upward from the vicinity of the lower end of the duct body so as to match the frequency of the room noise. It becomes possible to reduce the intake vibration by arranging the side branch in the side portion, and it is possible to improve the rigidity in the lower portion of the duct body by the first partition wall and suppress the occurrence of the intake vibration itself. .

Furthermore, the rigidity of the upper portion of the duct body is improved by the second partition wall which is inclinedly arranged on the upper portion of the duct body, and the intake air is rectified to the other duct passage divided by the first partition wall. It is possible to guide the air intake, and it is possible to improve the intake efficiency.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show an example of an embodiment for carrying out the present invention. In the figure, reference numeral 12 is connected to an air cleaner at its lower end through a boot and is erected upright like the air intake duct in FIG. The air intake duct fixed to the cab so that the reference numeral 13 indicates a duct main body forming an outer shell of the air intake duct 12.
The lower portion 13a is divided by a first partition wall 14 extending upward from the vicinity 14a of the lower end thereof, and the upper end of one duct passage divided by the first partition wall 14 is
The upper end 14b of the first partition 14 is bent by being formed in a lateral direction to be closed, whereby the one duct passage (the left passage in FIG. 1) has a closed pipe structure in which only the lower end is opened. It is formed as a side branch 15 which is a resonator of.

The lower portion 13 of the duct body 13 is also provided.
The other duct passage (right passage in FIG. 1) divided by the first partition 14 in a is used as an intake passage 16 for flowing intake air taken into the engine.

Further, a second partition wall 14 'is also formed on the upper portion of the duct body 13, and the second partition wall 14' is formed.
Is extended to the vicinity of the upper end opening 17 of the duct main body 13 from a lower end 14d which is arranged at a required distance 14c from the upper end 14b of the lower first partition wall 14 and is slightly spaced from the upper end 14b, and 13 A hood 18 at the top of the upper part 13 forms an opening 14f so as to straighten the intake air 19 which is folded back by approximately 180 ° and is introduced into the upper end opening 17 so as to be smoothly guided to the intake passages 16a, 16 and is slightly inclined. It is formed in the state.

That is, the above-mentioned upper second partition wall 14 '.
Is configured to divide the upper portion of the duct body 13 into substantially the same manner as the lower portion, and one of the divided duct passages 14e (the left passage in FIG. 1) is located directly above the side branch 15 and The other duct passage 16a (Fig. 1
The right-hand side passage) is continuous immediately above the intake passage 16.

The lower end 14d of the upper second partition 14 '
Is slightly separated from the upper end 14b of the lower first partition wall 14 because the dust accumulated on the upper surface of the side branch 15 can be removed and the intake noise is prevented. The lower portion of one duct passage 14e located immediately above the side branch 15 is connected to the other duct passage 16
Even if it is slightly communicated with a, the intake air that is folded back approximately 180 ° by the hood 18 at the top of the duct body 13 will flow along the inner peripheral surface of the hood 18 when folded back, so that it will be located directly above the side branch 15. Duct passage 14
Almost no flow of intake air is formed in e, and the intake passage 16 is rectified by the second upper partition wall 14 '.
The situation in which the flow of intake air guided to the is disturbed does not occur.

With such a structure, the length dimension L of the side branch 15 can be set upward from the vicinity of the lower end 14a of the duct body 13 so as to match the frequency of room noise. Therefore, the duct body 1
The side branch 15 can be arranged in the lower portion 13a of the duct 3 to reduce the intake vibration, and the rigidity of the lower portion 13a of the duct body 13 can be improved by the first partition wall 14 to prevent the intake vibration from occurring. Can be suppressed.

Furthermore, the rigidity of the upper portion of the duct body 13 is improved by the second partition wall 14 'which is inclinedly arranged on the upper portion of the duct body 13, and the intake passage 16 divided by the first partition wall 14 is provided. The intake air 19 can be rectified and guided, and the intake efficiency can be improved.

Therefore, even if the intake vibration is not reduced by a plurality of resonators only at the outlet of the air cleaner as in the conventional case, the air intake duct 12 having the structure as in the present embodiment can be integrally formed at a low cost by blow molding or the like. Since it is possible to effectively reduce the intake vibration, it is possible to eliminate or reduce the resonator,
Significant cost reduction can be achieved.

Further, since the intake air vibration can be effectively reduced in the lower portion of the air intake duct 12, the air intake vibration can be effectively reduced as in the conventional case where the side branch 15 is formed in the upper portion of the air intake duct 12. It is possible to solve the problem that intake vibration is newly generated in the lower portion of the intake duct 12, and it is possible to reliably reduce intake vibration and reduce indoor noise.

Further, a second partition wall 14 'is also formed on the upper portion of the duct body 13 so that the hood 1 on the top of the duct body 13 is formed.
Even if the side branch 15 is formed in the lower portion of the air intake duct 12, the intake air 19 that is folded back by the 8 and introduced into the upper end opening 17 is rectified and smoothly guided to the intake passage 16. Since the flow of the intake air 19 is not disturbed and the rigidity of the upper portion of the duct body 13 can be improved, intake vibration can be reduced more effectively and intake efficiency can be improved. it can.

The air intake duct of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

[0024]

According to the air intake duct of the present invention described above, various excellent effects as described below can be obtained.

(I) Since it is possible to set the length of the side branch upward so as to match the frequency of the room noise with the vicinity of the lower end of the duct main body as the starting point, the side branch is set at the lower side of the duct main body. The intake vibration can be reduced by arranging the first partition wall, and the rigidity of the lower portion of the duct body can be improved by the first partition wall to suppress the occurrence of intake vibration itself.

(II) Even if the intake vibration is not reduced by a plurality of resonators only at the outlet of the air cleaner as in the prior art, the intake vibration can be effectively reduced by the air intake duct that can be integrally molded at low cost by blow molding or the like. Therefore, the resonator can be eliminated or reduced, and the cost can be significantly reduced.

(III) Since intake air vibration can be effectively reduced in the lower portion of the air intake duct, the air intake duct can be formed as in the conventional case where the side branch is formed in the upper portion of the air intake duct. It is possible to solve the problem that intake vibration is newly generated in the lower part of the vehicle, and it is possible to reliably reduce intake vibration and reduce indoor noise.

(IV) By forming the second partition wall also in the upper portion of the duct body so that the intake air is rectified and smoothly guided to the intake passage, the side branch is provided in the lower portion of the air intake duct. Even if formed, the flow of intake air is not disturbed, and the rigidity of the upper portion of the duct body can be improved, so intake vibration can be reduced more effectively, and intake efficiency is improved. be able to.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of an embodiment for carrying out the present invention.

FIG. 2 is a view in the direction of arrows II-II in FIG.

FIG. 3 is a view in the direction of arrows III-III in FIG. 1;

FIG. 4 is a view in the direction of arrows IV-IV in FIG. 1;

FIG. 5 is a perspective view showing an arrangement state of a general air intake duct.

FIG. 6 is a plan sectional view showing a conventional example.

FIG. 7 is a side sectional view showing another conventional example.

8 is a view in the direction of arrows VIII-VIII in FIG. 7;

9 is a view in the direction of arrow IX-IX in FIG. 7.

FIG. 10 is a view in the direction of arrow XX in FIG.

[Explanation of symbols]

 1 Air Cleaner 3 Cab 9 Resonator 12 Air Intake Duct 13 Duct Body 14 First Partition 14 'Second Partition 15 Side Branch 17 Top Opening

Claims (1)

[Claims] 1. A lower portion of a duct main body, which is connected to an air cleaner through a boot at its lower end and is fixed to a cab so as to stand upright, extends upwardly by a required length upward from the vicinity of the lower end of the duct main body. Forming a partition wall and closing the upper end of one of the duct passages divided by the partition wall to form a side branch, the upper portion of the duct body,
The second partition wall extending from the position separated from the upper end of the first partition wall to the vicinity of the upper end opening of the duct body is rectified the intake air to the other duct passage divided by the first partition wall. The air intake duct is characterized by the slanted arrangement so that it can be guided.